Animate it ;-)

#!/usr/bin/perl
use Term::Cap;
$t= Tgetent Term::Cap;
$t=$t->Tgoto('cm', 0, 0);
for$i(1..shift){
  print $t;
  map{
    $a=1-$_/10;
    map{
      $d=$a;
      $e=$b=$_/20-2;
      map{
        ($d,$e)=(2*$d*$e+$a,$e**2-$d**2+$b);
        $c=$d**2+$e**2>4?_:0
      }1..$i;
      print$c
    }0..59;
    print$/
  }0..20;
}
[download]

Try perl mandel.pl 13. If I pass 99, there'll be a block of zeroes at the end.

<update>

It's not an overflow issue. As the area delimiting the mandelbrot converges to a line with increased iterations over the inner loop, there's not enough resolution to draw it. You can skip the outer area exiting the inner loop as soon as $d**2+$e**2>4

map{
  $a=1-$_/10;
  map{
    $d=$a;
    $e=$b=$_/20-2;
    for(1..99){
      ($d,$e)=(2*$d*$e+$a,$e**2-$d**2+$b);
      $c=$d**2+$e**2>4?_:0;
      last if $c eq _
    }
    print$c
  }0..59;
  print$/
}0..20;
[download]

I wonder how that works on your windows box, though.

</update>

--shmem

_($_=" "x(1<<5)."?\n".q·/)Oo.  G°\        /
                              /\_¯/(q    /
----------------------------  \__(m.====·.(_("always off the crowd"))."·
");sub _{s./.($e="'Itrs `mnsgdq Gdbj O`qkdq")=~y/"-y/#-z/;$e.e && print}

Very slick, ++shmem.

It's times like this I wish that replies to nodes could be front-paged on their own!

---

s''(q.S:$/9=(T1';s;(..)(..);$..=substr+crypt($1,$2),2,3;eg;print$..$/

LOL, nice, and demonstrates the problem neatly...

Tom Melly, pm@tomandlu.co.uk

Indeed, but then I lose at golf ;)

Here's my solution that avoids a last and only gains me a couple of strokes...

map{
  $a=1-$_/10;
  map{
    $d=$a;
    $e=$b=$_/20-2;
    map{
      ($d,$e)=(2*$d*$e+$a,$e**2-$d**2+$b);
      $c=$d**2+$e**2>4?$d=8:_
    }1..50;
    print$c
  }0..59;
  print$/
}0..20
[download]

Tom Melly, pm@tomandlu.co.uk

...probably some differences in handling of NAN / INF, etc. The algorithm makes your $d and $e values overflow rather quickly.

By reducing the number of iterations from 99 to something like 9 you should get a coarse approximation of the desired shape -- on both platforms.

Printing out the values of $d and $e on the respective platforms might give you a clue. The rendering of the floating point over/underflow on windows gives rise to a value that can be coerced to a number on Windows (or at least the version of Perl I have.

/J\

Gives me a rectangle of zeros on Windows.

Odd - I'm running activeperl build 810 (5.8.4) on Win2k, what about you?

map{$a=1-$_/10;map{$d=$a;$e=$b=$_/20-2;map{($d,$e)=(2*$d*$e+$a,$e**
2-$d**2+$b);$c=$d**2+$e**2>4?_:0}1..99;print$c}0..59;print$/}0..20;
[download]

Tom Melly, pm@tomandlu.co.uk

ActivePerl build 633 (5.6.1) on Win2k.

--

Oh Lord, won’t you burn me a Knoppix CD ?
My friends all rate Windows, I must disagree.
Your powers of persuasion will set them all free,
So oh Lord, won’t you burn me a Knoppix CD ?
(Missquoting Janis Joplin)